Ignore unexpected ICMPv6 Neighbor Discovery - Neighbor Solicitation packets

We need to adapt all functional traffic scripts related to functional
IPv6 tests to ingore receiving of unexpected ICMPv6ND_NS
(ICMPv6 Neighbor Discovery - Neighbor Solicitation) packets that are
sent automatically and we cannot avoid to receive them.

The reason is to prevent false negative test results in case of csit
functional tests that could block creation of new operational branch
(csit weekly jobs), usage of new vpp builds (csit semiweekly jobs)
and merging patches - csit as well as vpp.

Change-Id: I43c90e7c766762fa769a81661338759a11b401a1
Signed-off-by: Jan Gelety <jgelety@cisco.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/resources/traffic_scripts/ipfix_check.py b/resources/traffic_scripts/ipfix_check.py
index 2a08f0ce85..f5693cc7e8 100755
--- a/resources/traffic_scripts/ipfix_check.py
+++ b/resources/traffic_scripts/ipfix_check.py
@@ -24,8 +24,8 @@ from scapy.layers.l2 import Ether
 
 from resources.libraries.python.PacketVerifier import RxQueue, TxQueue, auto_pad
 from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
-from resources.libraries.python.telemetry.IPFIXUtil import IPFIXHandler, \
-    IPFIXData
+from resources.libraries.python.telemetry.IPFIXUtil import IPFIXHandler
+from resources.libraries.python.telemetry.IPFIXUtil import IPFIXData
 
 
 def valid_ipv4(ip):
@@ -123,6 +123,11 @@ def main():
         pkt = rxq.recv(10, ignore=ignore, verbose=verbose)
         if pkt is None:
             raise RuntimeError("RX timeout")
+
+        if pkt.haslayer("ICMPv6ND_NS"):
+            # read another packet in the queue if the current one is ICMPv6ND_NS
+            continue
+
         if pkt.haslayer("IPFIXHeader"):
             if pkt.haslayer("IPFIXTemplate"):
                 # create or update template for IPFIX data packets
@@ -138,9 +143,9 @@ def main():
 
     # verify packet count
     if data["packetTotalCount"] != count:
-        raise RuntimeError(
-            "IPFIX reported wrong packet count. Count was {0},"
-            " but should be {1}".format(data["packetTotalCount"], count))
+        raise RuntimeError("IPFIX reported wrong packet count. Count was {0},"
+                           "but should be {1}".format(data["packetTotalCount"],
+                                                      count))
     # verify IP addresses
     keys = data.keys()
     err = "{0} mismatch. Packets used {1}, but were classified as {2}."